Battery-powered wire insertion impact tool

Abstract

A battery-powered impact wire insertion tool that employs an electric motor to implement the impacting function. The electric motor is provided with suitable gearing that reduces its speed but increases its torque. An activator mechanism is employed to convert multiple revolutions of the motor shaft into a stored compressive force that after a predetermined number of shaft revolutions is triggered to release the compressive force to drive a hammer against an insertion blade mounted in the tool. The activator mechanism comprises axially-aligned cylindrical end cams with generally complementary surfaces that upon rotation of a driven cam axially extends a follower cam compressing a power compression spring, and upon encountering a cam lobe the driven and follower cams abruptly come together releasing the spring delivering the desired impact to the blade.

What is claimed is:  
     
       1. A tool for impact insertion of a wire into a terminal, wherein the tool comprises: 
       a) a gun-shaped housing with a front and a rear and a handle with a trigger mechanism,  
       b) electric motor drive means within the housing and having a shaft and with the drive means operatively connected to the trigger mechanism and including a planetary gear-down mechanism having an output for reducing the motor shaft speed while increasing its torque, said motor means and rear-down mechanism having a common axis,  
       c) a battery mounted in the housing and electrically connected to drive the motor,  
       d) an axially-arranged power compression spring having a rest position and a compressed position,  
       e) first means at the front of the housing for supporting a blade for inserting a wire into the terminal when impacted,  
       f) second means coupled between the power compression spring and the first means in response to multiple revolutions of the motor shaft for axially compressing the spring from its rest position into its compressed position and operative to suddenly release the compressed spring to impact the first means and in turn the blade,  
       g) said second means for axially compressing the spring comprising a driven cam rotatable with the gear-down mechanism and a follower cam mounted for axial movement and connected to the compression spring, said cams being configured such that a predetermined rotation of the driven cam axially moves the follower cam so as to move the compression spring from its rest to its compressed position,  
       h) third means for adjusting the impact force, said third means for adjusting the impact force comprising fourth means for axially adjusting the length of the compressed spring while in its released position.  
     
     
       2. A tool as claimed in  claim 1 , wherein the second means for compressing the spring comprises cylindrical cams with complementary cam surfaces and sharp cam lobes configured so as to cause the cam length to increase when rotated until the cam lobe is encountered. 
     
     
       3. A tool as claimed in  claim 1 , wherein the fourth means is located at the front of the gun. 
     
     
       4. A tool for impact insertion of a wire into a terminal, wherein the tool comprises: 
       a) a gun-shaped housing with a front and a rear and a handle with a trigger mechanism,  
       b) electric motor drive means within the housing and having a shaft and with the drive means operatively connected to the trigger mechanism and including a planetary gear-down mechanism having an output with reduced speed but with increased torque, said motor means and gear-down mechanism having a common axis,  
       c) a battery mounted in the housing and electrically connected to drive the motor,  
       d) an axially-arranged power compression spring having a rest position and a compressed position,  
       e) first means at the front of the housing for supporting a blade for inserting a wire into the terminal when impacted,  
       f) second means coupled between the power compression spring and the first means in response to multiple revolutions of the motor shaft for axially compressing the spring into its compressed position and operative to suddenly release the compressed spring to impact the first means and in turn the blade,  
       g) said second means for axially compressing the spring comprising a driven cam rotatable with the gear-down mechanism and a follower cam mounted for axial movement and connected to the compression spring, said cams being configured such that a predetermined rotation of the driven cam axially moves the follower cam so as to move the compression spring from its rest to its compressed position,  
       h) third means for adjusting the impact force, said third means for adjusting the impact force comprising fourth means for axially adjusting the length of the compressed spring while in its released position,  
       wherein the fourth means for axially adjusting the length of the compressed spring comprises a bushing connected to the spring and a rotatable collet mounted at the front of the tool for axially moving the bushing.  
     
     
       5. A tool as claimed in  claim 4 , wherein the bushing is connected to the driven cam for pushing the latter and the adjacent follower cam toward the spring to pre-compress it to increase the impact force. 
     
     
       6. A tool for impact insertion of a wire into a terminal, wherein the tool comprises: 
       a) a gun-shaped housing with a front and a rear and a handle with a trigger mechanism,  
       b) electric motor drive means within the housing and having a shaft and with the drive means operatively connected to the trigger mechanism and including a planetary gear-down mechanism having an output with reduced speed but with increased torque, said motor means and gear-down mechanism having a common axis,  
       c) a battery mounted in the housing and electrically connected to drive the motor,  
       d) an axially-arranged power compression spring having a rest position and a compressed position,  
       e) first means at the front of the housing for supporting a blade for inserting a wire into the terminal when impacted,  
       f) second means coupled between the power compression spring and the first means in response to multiple revolutions of the motor shaft for axially compressing the spring into its compressed position and operative to suddenly release the compressed spring to impact the first means and in turn the blade,  
       g) said second means for axially compressing the spring comprising a driven cam rotatable with the gear-down mechanism and a follower cam mounted for axial movement and connected to the compression spring, said cams being configured such that a predetermined rotation of the driven cam axially moves the follower cam so as to move the compression spring from its rest to its compressed position,  
       h) third means mounted at the tool front for adjusting the circumferential orientation of the blade.  
     
     
       7. A tool for impact insertion of a wire into a terminal, wherein the tool comprises: 
       a) a gun-shaped housing with a front and a rear and a handle with a trigger mechanism,  
       b) electric motor drive means within the housing and having a shaft and with the drive means operatively connected to the trigger mechanism and including a planetary gear-down mechanism having an output with reduced speed but with increased torque, said motor means and gear-down mechanism having a common axis,  
       c) a battery mounted in the housing and electrically connected to drive the motor,  
       d) an axially-arranged power compression spring having a rest position and a compressed position,  
       e) first means at the front of the housing for supporting a blade for inserting a wire into the terminal when impacted,  
       f) second means coupled between the power compression spring and the first means in response to multiple revolutions of the motor shaft for axially compressing the spring into its compressed position and operative to suddenly release the compressed spring to impact the first means and in turn the blade,  
       g) said second means for axially compressing the spring comprising a driven cam rotatable with the gear-down mechanism and a follower cam mounted for axial movement and connected to the compression spring, said cams being configured such that a predetermined rotation of the driven cam axially moves the follower cam so as to move the compression spring from its rest to its compressed position,  
       h) third means for controllably stopping the motor at a desired circumferential orientation of the blade.  
     
     
       8. A tool as claimed in  claim 7 , wherein the third means for controllably stopping the motor comprises opto-electronic means coupled to sense a predetermined amount of rotation of the gear mechanism and circuit means for dynamically braking the motor in response to a signal from the opto-electronic means. 
     
     
       9. A tool as claimed in  claim 7 , wherein the cams are configured to rotate one revolution to move the spring from its rest position to its compressed position and then to release it to restore its rest position.